ntirely
with Anjou. The most important is the chronicle called _Gesta consulum
Andegavorum_, of which only a poor edition exists (_Chroniques des
comtes d'Anjou_, published by Marchegay and Salmon, with an
introduction by E. Mabille, Paris, 1856-1871, collection of the
_Societe de l'histoire de France_). See also with reference to this
text Louis Halphen, _Etude sur les chroniques des comtes d'Anjou et
des seigneurs d'Amboise_ (Paris, 1906). The above may be supplemented
by some valuable annals published by Louis Halphen, _Recueil d'annales
angevines et vendomoises_ (Paris, 1903), (in the series _Collection de
textes pour servir a l'etude et a l'enseignement de l'histoire_). For
further details see Auguste Molinier, _Les Sources de l'histoire de
France_ (Paris, 1902), ii. 1276-1310, and the book of Louis Halphen
mentioned below.

(2) _Works_: The _Art de verifier les dates_ contains a history of
Anjou which is very much out of date, but has not been treated
elsewhere as a whole. The 11th century only has been treated in detail
by Louis Halphen, in _Le Comte d'Anjou au XI^e siecle_ (Paris, 1906),
which has a preface with bibliography and an introduction dealing with
the history of Anjou in the 10th century. For the 10th, 11th and 12th
centuries, a good summary will be found in Kate Norgate, _England
under the Angevin Kings_ (2 vols., London, 1887). On Rene of Anjou,
there is a book by A. Lecoy de la Marche, _Le Roi Rene_ (2 vols.,
Paris, 1875). Lastly, the work of Celestin Port, _Dictionnaire
historique, geographique et biographique de Maine-et-Loire_ (3 vols.,
Paris and Angers, 1874-1878), and its small volume of _Preliminaires_
(including a summary of the history of Anjou), contain, in addition to
the biographies of the chief counts of Anjou, a mass of information
concerning everything connected with Angevin history. (L. H.*)

ANKERITE, a member of the mineral group of rhombohedral carbonates. In
composition it is closely related to dolomite, but differs from this in
having magnesia replaced by varying amounts of ferrous and manganous
oxides, the general formula being Ca(Mg, Fe, Mn)(CO3)2. Normal ankerite
is Ca2MgFe(CO3)4. The crystallographic and physical characters resemble
those of dolomite and chalybite. The angle between the perfect
rhombohedral cleavages is 73 deg. 48', the hardness 3-1/2 to 4, and the
specific gravity 2.9 to 3.1; but these will v